The effects of antiseptics on dental plaque samples obtained from monkeys have been evaluated using conventional microbiologic as well as adenine nucleotide analysis. Consistent interpretations of the data were obtained from both methods. When the viable counts were normalized for the mass of the sample, a persistent reduction in viable count was noted after use of Octenidine. The persistent effect was supported by calculation of adenylate energy charge following analysis of the samples for three adenine nucleotides.